Receptance-Based Active Aeroelastic Control Using Multiple Control Surfaces

Design of next generation aircraft/sensorcraft for improved performance, such as gust load alleviation towards aircraft stability and flutter suppression during its flight operation, may necessitate wing technology that can be controlled and manipulated by active means. Moreover, in recent years the efforts are underway to realize “Fly by Feel” concepts, which are aimed in utilizing on-board sensors (embedded) and actuators (control surfaces) of the aircraft towards the design of active control system for desired performance. This paper presents active control strategies for wings having multiple control surfaces, which are purely based upon in-flight receptance (measured) data. The proposed receptance based control approach has several advantages over the traditional state-space based control because it circumvents approximation errors in reduced order modeling; it captures the true interaction between structure and aerodynamic loads; and it requires modest size of matrices (depending upon the available number of sensors and actuators) for control gain computations. In this study, multi-input state and output feedback control strategies for active aeroelastic control using the method of receptances is developed. The control gains are computed for the extension of flutter boundaries via pole placement. At first, by using numerical receptances obtained from the aeroelastic model of a flexible wing having multiple control surfaces, the proposed methodology is demonstrated. In order to test and demonstrate the receptance method for more complex aircraft geometries, configurations and aerodynamic loading conditions, numerical receptances from Finite Element models of aircraft wings with multiple control surfaces were extracted for the proposed control design. Presented studies and control approach may become the basis for optimal placement and sizing of control surfaces in a given wing section for active aeroelactic control and enhanced flight performance.